I have a problem with AVG also concerning l2.exe file.It says that it is infected with some trojan horse virus, but it can't be, because the exe is downl from retail.So I've add an exception to my AV, not to scan the game folder.I advise you to do the same and update your client using the retail Launcher=> LineageII.exe

Well I tried something this morning. I turned off my McAfee and put the vorbisfile back in place ran the game. when I logged out I had noticed that my McAfee had turned itself back on. So I tried to log in again and it worked. I am not sure how long it will work, perhaps it won't after my next shut down but at least I have a short way round.